Play Back of Clix g2 in auto
 

I am using an FM modulator to play my Clix G2 in auto. It is nice as I can take it easily from car to car especially rentals. I would like to have a better arrangement for my BMW 3 series and my wife's Jaguar S Type. Both cars have nice stock systems in them but both are 2005 so they predate the Blue tooth or direct plugs in. Without having a new head unit installed, do I have options? If not, will the usb on the Clix plug into one of the head units with usb for sound and control? I dislike Ipod (I have three gathering dust) but they do have good acessories. Bottom line what is the cleanest way to listen to my Clix in the car?

Thanks